What does the notation $p_t = \text{max}_{i<t} p_i$ mean in algorithm 1 of the prioritized experience replay paper?
From my interpretation what it means is that $p_t$ is the priority value associated with each transition and $p_t = max_{i&lt;t} p_i $ means that the priority of transition number $t$ will be the maximum between the values of the priorities of the previous elements.

Example: since $p_1$ is initialized to $1$, all the new experiences will be too:
\begin{equation}
p_2 = max\{p_1\} = 1,
\end{equation}

\begin{equation}
p_3 = max\{p_1,p_2\} = 1,
\end{equation}

\begin{equation}
p_4 = max\{p_1,p_2,p_3\} = 1.
\end{equation}